I don't recall specific measurements but…
The 350 fits in any factory short action stock from a 223 on up to the 350 and saum's and wsm's. The only difference is the magazine well. The 350 shares the mag box of the fatter saum and wsm cartridges.
I put my all weather 350 action into a laminate stock that came off of a 243. The only thing I had to do was widen the magazine well a few fractions of an inch. The barrel diameters were the same.